


It's Biology

by bluestbluetoeverblue



Category: Supernatural
Genre: F/M, High School AU, M/M
Language: English
Status: Completed
Published: 2014-10-15
Updated: 2014-10-15
Packaged: 2018-02-21 06:07:45
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,823
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2457656
Author URL: https://archiveofourown.org/users/bluestbluetoeverblue/pseuds/bluestbluetoeverblue
Summary: <blockquote class="userstuff">
              <p>In which Sam notices that his brother and his lab partner stare at each other a lot.</p>
            </blockquote>





	It's Biology

It all started with John. When Sam came home to tell his dad how ridiculously simple his freshman classes were, John had complained and pestered the school until Sam was moved into higher level classes. This landed him in AP biology, which Sam loved, but his senior classmates did not exactly love him. Thankfully, he’d gotten paired with Castiel Novak, one of the only upperclassmen willing to speak to him. 

Castiel was a grade A nerd if Sam ever saw one : teal, gray, and purple sweater vests, awkward square-rimmed glasses, kept a library of books in his locker--everything from To Kill a Mockingbird and Frankenstein to the Marvel comic books he occasionally let Sam borrow--and he rarely spoke unless asked a question. It was surprising that no one messed with Cas, but truth be told he was a needle in a haystack being completely ignored by all of the hay. Sam liked him. 

They were the best kind of lab partners; both did their work, they rarely disagreed, and Sam learned quickly that Cas’ silence was not rudeness, as most kids suspected. The first time they were assigned a formal lab report, Cas suggested that he come over on Saturday to work on it because his house was apparently full obnoxious siblings and suspicious parents. Sam understood the annoying sibling bit, and he agreed. 

“Hey Sammy, wanna see a movie?” Dean asked, bounding down the stairs in jeans and a black t-shirt. “I’m going with Charlie and Benny.”

“I’ve got school stuff, but thanks.” Dean shrugged and headed for the door just as a chiming noise sounded.

“We have a doorbell?” Dean asked, and Sam rolled his eyes as he opened the door to reveal Castiel, ruffled raven hair and leather messenger bag included. Dean gave him a questioning look before Sam walked up and told him to come in. Then Sam was the one getting the questioning look.

“Uh, Dean, this is my lab partner. Cas, this is my brother, Dean,” Sam said as they sat at the kitchen table. 

“Nice to meet you,” Castiel said with a raspy voice and a neutral expression. 

“Hey.” Dean’s eyes lingered on Cas a bit longer than they should have, but Sam didn’t notice. “Well I’m gonna go. Enjoy your unnecessary weekend homework. See ya later, Jerk.”

“Bitch,” Sam said as Dean escaped to the garage. 

“I didn’t think your brother knew how to make polite conversation,” Cas said, and Sam laughed.

“He puts up that rebellious, asshole front at school, but he’s actually pretty cool. Just don’t ever tell him I said that.”

 

It was Thanksgiving break when Cas came over for the day to work on biology again. He and Sam sat researching for a paper on the history of HeLa cells while Dean lounged on the couch in the living room doing, surprisingly, his own homework. 

“Jesus,” Dean said loudly.

“Hurt yourself trying to comprehend a real book?” Sam asked, the response to which was Dean coming into the kitchen to punch him on the shoulder. Cas watched the exchange with intrigue as Dean dropped his book on the table and took a seat beside Sam.

“Lady Macbeth is badass, man.”

Sam shook his head and went back to researching. He didn’t catch Cas smiling at Dean’s comment or Dean smiling at Cas’ smile. He sat quietly between them as the two smiled at each other then quickly looked away. Dean cleared his throat.

“Dad’s gotta work late, so I’m gonna make spaghetti for dinner.” He fled to the kitchen to root around in the pantry for noodles and cans of tomato sauce. 

About three weeks later, Sam was approached after class by Charlie Bradbury. Sam knew the redheaded techie well--she and Dean had been inseparable since seventh grade, which meant she and Sam had spent more than a bit of time together. Besides Cas, she was the only other senior in his bio class that didn’t resent him for being three years younger. That weekend, she and Cas met at the Winchester house to prep for their next test. Dean, having no plans, hung around the kitchen while the trio studied and quizzed each other, teasing Sam and Charlie when they missed something. When questioned, Dean claimed he was there for the cookies and chance at picking on his two favorite people. Sam did notice, though, the way he listened to Cas, eyes lingering on him after he spoke, after he ate up each raspy word. Cas was an intriguing guy, so he didn’t think much of it. 

Their study group met more often than most, probably because the three didn’t have many friends beside each other (except Charlie having Dean and her girlfriend, Dorothy and Cas having his multitude of rowdy siblings...okay maybe Sam was the one who didn’t have too many friends besides that sweet girl in his English class). Dean stuck around more often than not when the group met at his house, claiming that it was helping bring up his grade in regular biology class. That was before it all happened. 

 

Sam glanced at his watch for the fifth time, a knot of guilt forming in his stomach. Castiel was supposed to be showing up at the house in ten minutes. He tapped his foot impatiently, waiting for the line at the register to move. Why did Dean choose today to not bother picking up anything for dinner? John was working late, and Sam couldn’t even drive. He huffed and was vowing to do something to Dean next time he fell asleep on the couch watching Star Trek when he felt a tap on his shoulder. He turned to see a bright white smile and curly blonde hair. Jessica Moore. The girl from his English class. They’d worked together on a Shakespeare project, and he thought he was now quite possibly in love with her. Okay, maybe she was just really pretty and funny and kind and cared about her work and didn’t mind that he talked too much about...everything. Suddenly, meeting Cas on time didn’t seem like that big of a deal. 

Sam talked to Jess happily while he was checked out, then while she was checked out, then while walking outside, then for a few minutes standing around outside, and okay he was being kind of rude, but Cas would survive. By the time he was finally walking up to the house, groceries in hand, it had already happened. Cas was rushing out the front door, tan trenchcoat thrown on and messenger bag half open. Sam tried to stop him and explain why he was late, but Cas was hearing none of it, just saying it’s alright with wild blue eyes that wouldn’t look directly at him before hurrying to his car and away. 

Sam walked slowly into the house, feeling terrible about upsetting Cas. He really hadn’t thought his friend would mind waiting a bit. He found Dean standing in the living room. The middle of the living room. Sam did a double take, but the TV wasn’t on, and Dean didn’t appear to be doing anything. He was just standing there.

“Um, Dean?” The older Winchester looked up and after a second, and his face clicked back into its normal half I don’t care, half sarcastic expression. 

“Hey Sammy.”

“Did you let Cas in? Was he angry? I didn’t mean to be late.” Sam began putting the small amount of food he’d bought away, not noticing that Dean was still standing awkwardly in the middle of the room.

“Um, no, don’t worry. I don’t think he’s mad at you. I’ll, uh, see you later.”

“Whatever,” Sam said as Dean started up the stairs, his thoughts already turning from Cas and his brother to Jess.

After that, Cas didn’t come over for a while. Sam went over to his house more often, braving prolonged exposure to Gabriel, Anna, Balthazar, and the rest of the Novak family. Dean stopped hanging around during study sessions with Charlie. Finally, Cas gave in and spent a Friday afternoon at the Winchester kitchen table, going over lab reports. Just as Sam was standing up to go find his misplaced notebook, Dean came in the front door, leather jacket damp from the rain. 

“Hey Sam, is Dad-” Dean was cut off when he looked up. “Castiel. Uh, hi.”

“Hello Dean,” Cas said quietly. 

“I’ll be right back.” Sam ran upstairs and dug around in piles of clothes and books until he finally found his notebook. When he returned, Dean and Cas were sitting silently at the table, Cas pretending to be interested in his textbook while Dean picked at the sleeve of his jacket. Sam didn’t notice, but Dean threw Cas a small, soft smile as he left. After that, Dean again always managed to be in the room when they were studying or working on homework, usually sitting at the table with them.

They were staring again. Sam sighed and focused his eyes on the diagrams in his text book. At first it had been sort of cute; Dean would glance at Cas when he wasn’t looking, Cas would glance at Dean when he wasn’t looking, they had been ridiculous and pitiful and very entertaining, but it wasn’t cute anymore. He was distracted by his brother and his lab partner/friend blatantly staring at each other, blue eyes into green. Then one of the idiots would occasionally lick his lips, and Sam would cringe, sometimes coughing loudly or asking Cas some stupid question about cellular respiration to separate their stares. After a while, he couldn’t take it anymore.

“Do you guys want a room?” he asked. They both looked up at him, confused, and Cas tilted his head.

“I’m sorry?” Dean said for them.

“I can’t take it anymore! Look, I don’t care if you guys wanna talk or make out or whatever, but do it some other time. Just let me study in peace or I’m going to start working with Charlie on everything.” 

They were both speechless. 

“What are you talking about?” Dean asked, giving Cas a flash of shame. Sam just rolled his eyes and went back to his book. As much as Dean wanted to play dumb, it all worked out eventually. He wasn’t allowed downstairs while Cas and Sam were studying and any other time Dean and Cas were free to talk (which they did a lot of) and make out (which they did even more of). By the end of the semester, Dean and Castiel were joined at the hip any time except Tuesdays and Fridays from three to five. And they were both there to help Sam prepare (alright Dean was more teasing than helpful but still) for getting pizza with Jess. All in all, the only thing Sam Winchester had left to worry about was passing the AP exam. Luckily, he had a great study group.


End file.
